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The scalable fabrication of flexible membranes for efficient oil/water separation is in high demand but still significantly underdeveloped. Here, we present a flexible membrane using Ti3C2Tx (MXene) as the functional layer on conventional print paper as the substrate. With a simple coating process using MXene ink, we developed a highly hydrophilic and oleophobic membrane with an underwater oil contact angle of 137°. Such a simple membrane shows outstanding flexibility and robustness, and demonstrates a facile approach for membrane scale-up using MXene ink on low-cost print paper. The membrane shows high separation efficiency for oil/water emulsions, of over 99%, and a high water permeation flux of over 450 L per m2 per h per bar. We demonstrate the excellent anti-fouling property of this membrane by cleaning the membranes without chemicals. These low-cost, highly efficient, anti-fouling membranes can provide new opportunities for industrial oil/water separation applications. Other information Published in: RSC Advances License: https://creativecommons.org/licenses/by-nc/3.0 See article on publisher's website: http://dx.doi.org/10.1039/c9ra02129a

In the last decade, studying of thermal energy storage systems using phase change material (PCM) in the field of building has been increasingly developed. Indeed, it decreases the energy consumption used for indoor heating system while maintaining maximum thermal comfort for the occupants. This paper presents a study on application of white petroleum jelly, which is used as a phase change material, with an electrical under floor heating system. To proceed, a prototype of a well-insulated house is constructed. An experimental study was carried out in a relatively cold weather to investigate the thermal behavior of using phase change material. Results show that at an average ambient temperature QUOTE of 14℃ the electrical consumption was shifted by an average of 6 hours due to the latent heat stored in PCM.

Researchers are continually striving to improve the efficiency of photovoltaic panels which contain solar cells that convert light energy to electrical energy. The objective is to improve photovoltaic (PV) efficiency by maintaining it below maximum allowable temperature. Accordingly, the excess in heat must be dissipated efficiently in order to avoid excessive high temperatures, which have an adverse effect on the electrical performance of the cell. Therefore, in this paper an experimental study is presented to enhance the performance of PV panels using Aluminum finned plate, and cooling under natural convection. The use of heat sinks has been conducted to address this problem by using an optimum design of Aluminum finned plate. The results show that the use of an Aluminum finned plate has increased the solar to electrical conversion efficiency by 1.75%, and the output power by 1.86 Watt.

The electrical efficiency of a photovoltaic panel PV is highly dependent on its temperature. When the temperature of a PV increases, its electrical efficiency decreases. Using Phase Change Material PCM is one of the most promising tools nowadays to reduce and regulate the temperature of a PV panel and to increase its electrical efficiency. The current research is based on experimental studies of the effect of using pure (White petroleum jelly) and combined PCM (white petroleum jelly, copper, and graphite) on the thermal behavior and electrical performance of a PV panel. A transient energy balance is also presented to analyze the system thermal behavior and correlate it to the electrical outputs. To proceed, an appropriate experimental setup was devised and three prototypes were constructed and tested. Prototype 1 is formed from a reference case and consists of a stand, a PV panel, and an electrical circuit with a given load. Prototypes 2 and 3 are designed with a container added at the rear face of each PV panel that holds pure PCM and combined PCM respectively. It was shown that the electrical efficiency of PV panels has been increased by an average of 3% when using pure PCM and by an average of 5.8% when using combined PCM. These enhancements as well the corresponding behaviors were demonstrated by a transient energy balance approach.

Designing energy recovery systems that are pollution free has become a significant goal within the research community. One of numerous systems that have been proposed is Speed Bump Power Generator SBPG system that produces electrical power by utilizing the movements of commuting vehicles on highways, boulevards, and streets. When vehicles pass over a SBPG system, the system translates vertically. Consequently, a kinetic energy is produced and transferred into electrical power. In this paper, different types of SBPG systems are presented. An experimental analysis is performed on the rack-and-pinion system. Results have shown that electrical power up to 45 W generated when a mass of 80 kg is applied to SBPG system considered. Extrapolation of results confirms around 0.56 kW powers can be produced when various vehicles with different masses pass through the bumps.

The thermal soak phase of a vehicle results from driving the vehicle at high load followed by shutting off the engine. The present work deals with the analysis and modeling of the thermal soak phase of a vehicle through temperature and heat flux measurements. Measurements are carried out on a passenger vehicle in wind tunnel S4 of Saint-Cyr-France. The underhood is instrumented by alsmot 120 surface and air thermocouples and 20 fluxmeters. Measurements are performed for three thermal functioning conditions, with the engine in operation and the front wheels positioned on the test facility with power-absorption controlled rollers. It was found that in thermal soak the temperature of certain components can increase by almost 80A degrees C (pre-catalyst) and that of air zones by alsmot 40A degrees C (crawl area). These components correspond to areas that heat up after stopping the engine for 3 to 24 minutes, depending on their position in the underhood and on the thermal operating point considered.

International audience; In this paper, a domestic thermoelectric cogeneration system (DCS) is suggested. This system permits to use the lost heat of exhaust gases to simultaneously heat water and produce electricity via thermoelectric generators (TEG). To proceed, the concept of the system is drawn and the corresponding thermal modeling is developed. An optimization analysis, based on the position of the thermoelectric generators within the system, is carried out using the thermal modeling. The TEGs are places on the inner or outer walls of the tank or the pipe (cases 2–5), or on all of them (case 6). Results show that water can be heated to up to 97 °C, when TEGs are located on the inner wall of the tank. More the TEGs are nearer to the exhaust gases, higher is the total power produced by the TEGs and lower is the water temperature. The power produced by one TEG in direct contact with the exhaust gases is 0.35 W and the water temperature is 76 °C. Also, a DCS with TEG located at all layers can generate up to 52 W and 81 °C hot water, however this configuration has high initial cost. An economic and environmental concerns are considered. Results show that DCS with TEGs located on the inner wall of the pipe has a payback period of 1 year and 8 months when water is heated 60 times per month. In addition to that, it was shown that the location of TEGs do not affect the amount of CO2 gas reduced which is about 6 tons yearly. Finally, this study shows that the configuration where TEGs are placed at the inner wall of the pipe is the most cost-effective energy recovery configuration.

Computer-aided diagnosis (CAD) systems have become very important for the medical diagnosis of brain tumors. The systems improve the diagnostic accuracy and reduce the required time. In this paper, a two-stage CAD system has been developed for automatic detection and classification of brain tumor through magnetic resonance images (MRIs). In the first stage, the system classifies brain tumor MRI into normal and abnormal images. In the second stage, the type of tumor is classified as benign (Noncancerous) or malignant (Cancerous) from the abnormal MRIs. The proposed CAD ensembles the following computational methods: MRI image segmentation by K-means clustering, feature extraction using discrete wavelet transform (DWT), feature reduction by applying principal component analysis (PCA). The two-stage classification has been conducted using a support vector machine (SVM). Performance evaluation of the proposed CAD has achieved promising results using a non-standard MRIs database.

The main purpose of this paper is to design a clean and stand-alone power generator for isolated sites using renewable energy sources. The proposed system is able to operate without the need of refueling. The idea is to combine Photovoltaic Panels (PVs) with Fuel Cell (FC) to build an uninterrupted power generator. In presence of solar energy, PVs are used to feed the site with the required power as well as to produce hydrogen and oxygen using an electrolyzer. When solar energy becomes insufficient, the stored hydrogen and oxygen are used to feed the FC and produce electricity. The proposed system is modeled and controlled using Matlab-Simulink.

International audience; Numerical simulation becomes essential in manufacturing large part by incremental forging processes. It is a splendid tool allowing to show physical phenomena however behind the scenes, an expensive bill should be paid, that is the computational time. That is why many techniques are developed to decrease the computational time of numerical simulation. Multi-Grid method is a numerical procedure that permits to reduce computational time of numerical calculation by performing the resolution of the system of equations on several mesh of decreasing size which allows to smooth faster the low frequency of the solution as well as its high frequency. In this paper a Multi-Grid method is applied to cogging process in the software Forge 3. The study is carried out using increasing number of degrees of freedom. The results shows that calculation time is divide by two for a mesh of 39,000 nodes. The method is promising especially if coupled with Multi-Mesh method.

We report here experimental results focused on the optimization of vehicle underhood cooling module. These results constitute the basis for a new approach of controlling the cooling module positioning according to the engine energy requirements. Measurements are carried out on a simplified vehicle body designed based on the real vehicle front block. We report here velocity and temperature measurements by Particle Image Velocimetry (Ply), by Laser Doppler Velocimetry (LDV) and by thermocouples. The underhood of the simplified body is instrumented by 59 surface and fluid thermocouples. Measurements are carried out for conditions simulating both the slowdown and the thermal soak phases with the fan in operation. Different fan rotational speeds, radiator water flow and underhood geometries have been experimented. The ultimate aim is to apply the new control approach to a real vehicle so as to reduce the energy delivered to the pump and compressor and therefore to reduce the vehicle fuel consumption. (C) 2011 Elsevier Ltd. All rights reserved.

The present paper reports a numerical investigation of spatial optimization of heat-exchanger by acting on its positioning in the vehicle's cooling module. This analysis also elucidates how to act on the different parameters influencing heat-exchanger performance in order to optimize their functioning. A two-dimensional computation code permits optimizing the performance of the cooling module by positioning different heat exchangers, in both the driving and stop phases of the vehicle. The ultimate aim is to apply new control approaches to real vehicles so as to reduce pump and compressor energy consumption and thus fuel consumption. Compared to a reference "in-series" configuration of the cooling module HXs (in which the different HXs are superposed in the airflow direction), an "in-parallel" configuration (in which the different HX surfaces are in a row with respect to the air flow direction) increases the thermal power of the HXs by 4.4% and decreases the pressure losses by 0.9%. (C) 2011 Elsevier Ltd. All rights reserved.

Solar energy can be utilized mainly in heat generation and electricity production. International energy agency (IEA) shows, in a comparative study on the world energy consumption that in 2050 solar arrays installation will provide about 45% of world energy demand. Solar energy is one of the most important renewable energy source which plays a great role in providing energy solutions. As known there is wide variety of types of collectors and applications of solar energy. This paper aimed to make a short review on solar energy systems, according to types of collectors and applications used.

This paper concerns an experimental study on a system of heat recovery applied to domestic drain water pipes. The concept suggested consists of using the heat still present in the drain water as a preheating/heating source to the cold water supply of the building. To proceed, an appropriate experimental setup is developed and a coil heat exchanger is used as heat transfer device in the recovery system. Several scenarios are simulated and corresponding parameters are recorded and analyzed. It was shown that the suggested recovery concept can considerably preheat the cold water supply and then decrease the energy consumption. Particularly, up to 8.6 kW of heat were recovered when the cold water supply is initially at 3 °C.

International audience; In the last decade, a tremendous effort has been made to find solutions permitting to decrease the consumption of fossil energy. Energy recovery is one of the emerging solutions. It consists in recuperating the waste energy that exists in many systems and reutilizing it in a useful way. Heat recovery from hot water drain is one of energy recovery systems that is taking its reputation nowadays due to the major part of the electric bill occupied by heating domestic water. This paper reports a calculation procedure that can be applied to many drain heat recovery systems. It can be utilized as a pre-calculation tool to evaluate and analyze drain heat recovery systems or as an optimization technique to enhance an existing system. To proceed, a generic experimental setup is devised and a parametric experimental analysis is performed using the developed setup. Experiments have shown that the system can considerably increase the temperature of the cold supply water for some configurations. Based on experimental results, many drain systems can be preliminary evaluated and analyzed using a new suggested systematic calculation procedure based on experimentally determined parameters.

Parametric numerical analysis that explores the relation between the non-uniformity of air temperature distribution upstream of a heat exchanger and its thermal performance is performed. The obtained numerical results are employed toward the optimization of water-air heat exchanger thermal performance. Furthermore, the numerical results lay out the foundation to develop an innovative control approach for monitoring the airflow upstream of a cross-flow water-air heat exchanger that lead to the optimization of its thermal performance and energy consumption. Consequently, an in-house computational code is established to evaluate the aforementioned thermal performance based on known parameters; namely, distribution of upstream velocity and temperature of an air-liquid heat exchanger, the flow rate of heat exchanger liquid, in addition to the inlet liquid temperature. It was observed that non-uniformities in air temperature can, depending on the configuration, increase or decrease the thermal performance of a heat exchanger up to 5%. Additionally, controlling air temperature non-uniformities, the fuel consumption and carbon dioxide emission can be reduced by up to 0.97 kg (1.34 L) and 3.17 kg respectively for a vehicle running three hours per day. (C) 2016 Elsevier Ltd. All rights reserved.

The last decade has witnessed a tremendous effort to find solutions permitting to decrease the consumption of fossil energy. Energy recovery is one of the solutions. It consists in recuperating the waste energy that exists in many systems, and reutilizing it in a useful way. In this paper, a technique to recover the heat of the shower drain water is proposed. The design is presented as well as a design calculation allowing sizing the system. A prototype is constructed. The increase in temperature that can be reached using the proposed system is evaluated using the prototype. Experiments have shown that the proposed system can increase the temperature of the cold supply water by 14°C.

In the present study, the most important parameters that affect the performance of a solar chimney power plant are investigated. The plant has a collector area of 7000 m diameter and a tower of 1000 m height. Under certain weather conditions, the results obtained show that the maximum electrical power of this plant can be reached in June and can be up to 119 MW. This amount of electrical power, which depends on the dimensions of the plant, is able to provide electricity for more than 150,000 households, which makes this type of plants vital for countries like Lebanon.

The present work concerns a prototype implementation and an experimental study of a new design of water heating using parabolic troughs equipped with solar tracking system. Combining the two techniques of parabolic troughs and solar tracking permits to enhance the water heating by solar energy. A prototype is implemented to test the proposed approach. An experimental study is carried-out to test the performance of the system as well as the effect of the weather conditions on the system. The effect of each technique is evaluated separately by performing experiments with and without solar tracking and with/without parabolic mirrors. It is shown that with a parabolic trough of 0.6 m2 area, water can be heated from 23 to 57 °C. Moreover, the temperature can reach 69 °C when the tracking system is activated.Copyright © 2014 by ASME

The leakage areas of the engine compartment are located essentially at the junctions between the hood and the front end, the sides, the lights, and the windshield. The present study concerns the impact of these leakage zones on the engine compartment temperatures. The study synthesizes thermal measurements carried out on a real vehicle in the wind tunnel S4 of Saint-Cyr l’Ecole France. The engine compartment is instrumented with 80 surface and air thermocouples. Measurements are carried out for three different thermal functioning points with the front wheels of the vehicle positioned on a dynamometer and driven by the engine of the car. Five configurations of leakages closing are tested.

The high cost of fuel energy and the dangerous rate of pollution push researchers to find new sources of energy. Energy recovery is one of these solutions. It allows producing energy without any pollution effect. Speed bump power generator (SBPG) is a system allowing producing power from the cars moving on the road. When the car passes over a SBPG, a mechanical system absorbs its kinetic energy and transfers it into electrical power. In this paper, the different types of SBPG are presented. A prototype is constructed and experiments are carried out. One can generate up to 65 W when a mass of 85 kg is applied to the bump. An extrapolation calculation shows that these powers can be around tens of kW when vehicles of tons-masses pass through the bumps.

This paper presents an experimental investigation of the underhood thermal behaviors during vehicle thermal soak (when the vehicle stops after a large thermal load) by temperature measurement and separate measurements of convective and radiative heat fluxes. Measurements are carried out on a passenger vehicle in wind tunnel S4 of Saint-Cyr-France. The underhood is instrumented by almost 120 surface and air thermocouples and 20 fluxmeters. Measurements are performed for three thermal functioning conditions, with the engine in operation and the front wheels positioned on the test facility with power-absorption controlled rollers. It was found that in thermal soak the temperature of certain components can increase by almost 80°C (pre-catalyst screen) and that of air zones by almost 40°C (crawl area).Copyright © 2013 by ASME

This paper concentrates on the assessment of automobiles aerothermal management; namely, the consequence of the architectural arrangements of electrical and mechanical components on the aerothermal behavior in the underhood compartment. Consequently, it is natural to review the architectural arrangements of underhood components implemented by automotive companies such as Renault, Peugeot, Audi, BMW, Mercedes, Volvo, General Motors, Jaguar, Land Rover, Porsche, Nissan, Chrysler, Ford, Hyundai, Kia, and Toyota. Moreover, this study will evaluate the qualitative impact of each individual component on the aerothermal environment of the underhood. Furthermore, the study is determined to examine explicitly the components architectural arrangements' of underhood compartments and present simplified models of the compartments so that they can serve as aerothermal baseline models in the early stages of design. Hence, the different components in the underhand compartment are classified with respect to aerothermal orders of impact. Followed, two geometrical models, simple and advanced, are developed based on the impact orders. These models serve for future aerothermal studies (analytical, numerical and experimental). Finally, a simplified vehicle model is designed and implemented as underhood compartment model. The structurally simplified model is already utilized in experiments and can be used afterward in both numerical and experimental analyses. (C) 2014 Elsevier Ltd. All rights reserved.

This paper presents a numerical analysis focused on the relation between non-uniformities in flow velocity and temperature distributions upstream of heat exchangers and their thermal performance. For this purpose, a two-dimensional computation code is developed to compute thermal performance, knowing the air flow velocity distribution upstream of an air-liquid heat exchanger, the heat exchanger liquid flow rate and the air and liquid inlet temperatures. A parametric analysis is then presented of the relation between the thermal performance of the heat exchanger and the different parameters above. It is found that non-uniformities in air velocity and water flow distributions can decrease the thermal performance of a heat exchanger from 33 to 42%. However, non-uniformity in the air temperature distribution can increase thermal performance by up to 5%.Copyright © 2013 by ASME

This work reports on experiments carried out on a real passenger vehicle in a large wind tunnel to investigate the effects of car inclination on underhood cooling. The vehicle’s underhood is instrumented by thermocouples that measure the temperatures of many underhood components during different car functioning modes. Measurements are carried out for three thermal functioning points at car speeds 90, 110 and 130 km/h. In these experiments the engine was in operation and the front wheels positioned on the test facility with power-absorption-controlled rollers. Three car inclinations are investigated: flat, uphill and downhill. The results show that car inclination, even if very small, can have significant effects on underhood cooling and must be taken into consideration in numerical simulations and controlled in experimental tests. It was shown that down-hill and up-hill inclinations increase temperatures of components, air zones and engine parameters in the underhood, with higher effect for the down-hill inclination. Temperature increases in constant-speed driving phase are higher than in thermal soak phase.

The aerodynamic torsor of a vehicle is among the most crucial parameters in new car development. This torsor has been decreased over the years by more than 33%, but beyond that further improvement has become difficult and challenging for car manufacturers. In this context, the present paper focuses on a parametric analysis of the trends in the aerodynamic forces. We report here aerodynamic force measurements carried out on a simplified vehicle model. Tests were performed in wind tunnel S4 of Saint-Cyr l'Ecole for different airflow configurations in order to isolate the parameters that affect the aerodynamic torsor and to confirm others previously suspected. The simplified model has flat and flexible air inlets and several types of air outlet, and includes in its body a real cooling system and a simplified engine block that can move in the longitudinal and lateral directions. The results of this research, which can be applied to any new car design, show configurations in which the overall drag coefficient can be decreased by 2%, the aerodynamic cooling drag coefficient by more than 50% and the lift coefficient by 5%. Finally, new designs for aerodynamic drag reduction, based on the combined effects of the different parameters investigated, are proposed. (C) 2012 Elsevier Ltd. All rights reserved.

The present paper reports an experimental study of the aerothermal phenomena in the vehicle underhood compartment as investigated by measuring temperature, convective heat flux, and radiative heat flux. Measurements are carried out on a passenger vehicle in wind tunnel S4 of Saint-Cyr-France. The underhood space is instrumented by 120 surface and air thermocouples and 20 fluxmeters. Measurements are performed for three thermal functioning conditions while the engine is in operation and the front wheels are positioned on the test facility with power-absorption-controlled rollers. In the thermal analysis, particular attention is given to measuring absorbed convective heat fluxes at component surfaces. It is shown that, in some components, the outside air entering the engine compartment (for cooling certain components) can in fact heat other components. This problem arises from the underhood architecture, specifically the positioning of some components downstream of warmer components in the same airflow. Optimized thermal management suggests placing these components further upstream or isolating them from the hot stream by deflectors. Given style constraints, however, the use of air deflectors is more suitable than underhood architectural changes. Much of the present paper is devoted to heat flux analysis of the specific thermal behaviours in the underhood compartment (especially the absorption of convective heat fluxes) and to a description of a new control approach exploiting air deflectors to optimize underhood aerothermal management. (C) 2010 Elsevier Ltd. All rights reserved.

An experimental analysis of the aerothermal phenomena in the vehicle underhood is given using temperature measurements and separate measurements of convective and radiative heat fluxes. The vehicle underhood used for these measurements is instrumented by 120 surface and air thermocouples and 20 fluxmeters. Measurements are carried out on a passenger vehicle in wind tunnel S4 of Saint-Cyr-France for three thermal functioning conditions. In particular, it is shown for some components that outside air entering the engine compartment (for cooling the different components by convection) can in fact heat other components. This problem results from the underhood architecture, specifically the positioning of some components downstream of warmer components in the same airflow. To avoid this undesired situation, an optimized thermal management procedure is proposed that uses static and dynamic air deflectors during the constant-speed driving (rooting) phase of a vehicle. Much of the present paper is devoted to fluxmetric analysis of underhood thermal behavior (especially the absorption of convective heat flux); we also describe a new control procedure for implementing air deflectors in the actual car underhood.Copyright © 2010 by ASME

Here numerical analysis is focused on optimizing the vehicle heat exchanger by varying the geometry in which it is integrated in the vehicle’s cooling system. This analysis also elucidates how one can affect the different parameters that influence heat exchanger performance in order to optimize their functioning, in relation to the geometry in which they are integrated. The two-dimensional computational code developed permits optimizing the performance of the cooling module by positioning different heat exchangers, in both driving and stop phases of the vehicle. The ultimate aim is to develop new approaches to controlling heat exchanger positions in a real vehicle cooling system.

It is now well established that car inclination influences component temperatures in the car underhood compartment [1, 2]. This study presents an analysis of these effects by measurement of the heat flux that enters or leaves the underhood components. We report underhood thermal measurements carried out in wind-tunnel S4 of Saint-Cyr l’Ecole on a passenger vehicle. The underhood compartment is instrumented with 40 surface and air thermocouples and 20 fluxmeters of normal gradients. Three configurations of car positions are investigated: the flat, the up-hill and the down-hill inclinations. Measurements are carried out for three different car thermal functioning points.Copyright © 2010 by ASME

Aerodynamic cooling drag, caused by car underhood cooling, can be reduced by better underhood aerothermal management. This study addresses the aerothermal phenomena encountered in the vehicle underhood compartment by physical analysis of the heat transfer modes in complex internal flows. We report here underhood heat flux and temperature measurements on a vehicle in wind tunnel S4 of Saint-Cyr-France using a new experimental method. The underhood is instrumented by 40 surface and air thermocouples and 20 fluxmeters. Measurements are carried out for three thermal functioning points: the engine in operation and the front wheels positioned on the test facility with power-absorption-controlled rollers. The ultimate aim is to reengineer the underhood architecture so as to reduce the cooling air flow rate in the underhood component and hence the aerothermal cooling drag. (C) 2009 Elsevier Ltd. All rights reserved.

The study presented here concerns the impact of car inclination on the temperatures in the vehicle underhood compartment. We report here underhood thermal measurements carried out on a vehicle in wind tunnel S4 of Saint-Cyr. The underhood is instrumented by 80 surface and air thermocouples. Measurements are carried out for three thermal functioning points: the engine in operation and the front wheels positioned on the test facility with power-absorption-controlled rollers. Three car inclinations are tested.